1. Field of the Invention
This invention relates to weather strips provided along openings of an automobile.
2. Description of the Prior Art
The prior art concerning the invention will be described with reference to weather strips provided for the luggage room and a door window of an automobile.
In the case of the luggage room, a flange is formed along the opening of the luggage room, and a weather strip having a trim part and a seal part is fastened to the flange (U.S. Pat. No. 4,603,899).
A typical example of the weather strip of this type is as shown in FIG. 7. The weather strip 4' includes a trim part 41 which is fastened to the flange 2 of a panel 22 of the vehicle body and a hollow seal part 42 which extends from the trim part 41. More specifically, the trim part 41 is U-shaped in section having two opposite side walls, and the seal part 42 extends from the common top portion of the two opposite side walls, and is pushed by a luggage room door 3 from above. Generally, a core member 45 is buried in the trim part 41 so as to prevent the deformation of the latter 41, and the trim part 41 has a body seal lip 43 which is brought into contact with the body panel 22.
There is a tendency to, in order to facilitate the loading of luggage in or the unloading of luggage from the luggage room, modify the luggage room in such a manner, as shown in FIG. 2, so that the middle portion of the rear wall is removed, and instead, a vertical wall 31 is added to the luggage room door 3.
In the case of the luggage room 11, a weather strip 4' should be fastened to the flange 2 in such a manner that the seal part 42 faces upward for the ranges A and B, and backward of the vehicle body for the ranges C and D. Accordingly, the flange 2 is protrudes upward between A and B, and protrudes backward between C and D. That is, the flange 2 is three-dimensionally changed in posture and in direction.
When the weather strip 4' is engaged with the flange 2, the hollow seal part 42 and the body seal lip 43 are deformed at the corners of the ranges A, B, C and D as shown in FIG. 8. In FIG. 8, reference character 4'(A) designates the weather strip 4' which is not deformed yet. At the corner between the ranges A and B, the weather strip 4' is bent substantially 90.degree. with the seal part facing upward. In this case, as indicated at 4' (B) in FIG. 8, the bending central axis (a) is inside the luggage room 11, as a result of which the weather strip's portion outside the luggage room 11 is pulled, whereby the hollow seal part 42 falls inside of the luggage room 11 while the body seal lip 43 falls below the luggage room 11. At the corner between the ranges B and C, the weather strip 4' is bent about 90.degree. and twisted in such a manner that the seal part 42 faces backwards from its upward direction. In this case, the bending central axes (b) and (c) are located as indicated at 4' (C). Therefore, the upper portion of the weather strip, as well as the portion of the weather strip that is located inside the luggage room 11, is pulled. As a result of this pulling, the hollow seal part 42 is deformed in such a manner that it falls outside the luggage room 11 as indicated by the arrow and collapses downward. Furthermore, at the corner between the ranges C and D, the weather strip 4' is bent about 90.degree. with the seal part faced backwards. In this case, the bending central axis (d) is as indicated at 4' (D). That is, the axis (d) is located in the upper portion of the weather strip. Hence, the lower portion of the weather strip is pulled, as a result of which the weather strip is deformed in such a manner that the hollow seal part 42 and the body seal lip 43 fall upwards as indicated by the arrow.
The above-described deformation of the hollow seal part 42 and the body seal lip 43 at the corners makes the sealing line of the weather strip irregular, thus lessening the sealing effect of the weather strip.
In the case of a door window of an automobile, as shown in FIG. 6, a weather strip 5A is provided along the inner periphery of a door frame 10 which forms a window opening in a door 1. As shown in FIG. 11, a weather strip 5B is provided along a door opening 23 in a body panel 22. In general, each of these weather strips includes a trim part U-shaped in section engaged with a flange provided along the door opening 23 or door frame 10 and a seal part extending from the trim part so that it is located away from the vehicle body when installed.
FIG. 9 shows the structure of the door weather strip 5A. The trim part 51 is engaged with a flange 32 of the door frame 10. The seal wall 50 of the seal part 52 is pushed by the edge of a window glass plate 24 as the glass plate 24 is moved so as to close the window. A separable core member 56 (which is separable into a plurality of core pieces) is buried in the trim part 51.
When the weather strip 5A is bent at the corner C.sub.1 (FIG. 6) with the opening of the trim part 51 on the outside diameter side, then, as shown in FIG. 10 the bending central axis (a.sub.1) is formed in the bottom portion on the inner diameter side. Therefore, a tensile force acts on the outer diameter side, so that the seal part 52 falls in the direction of the arrow that is, it falls away from the door frame 10. As a result, the sealing line shifts, and a gap (d) is formed between the door frame 10 and the weather strip 5A, thereby lessening the sealing effect of the weather strip 5A.
FIG. 12 shows the weather strip 5B provided along the door opening 23. The trim part 51 is engaged with the flange 2 of the door opening 23 in the body panel 22. The seal part 52 is pushed by the door frame 10 when the door is closed. When the weather strip 5B is bent at the corner C.sub.2 (FIG. 11), the bending central axis (a.sub.2) is formed in the bottom portion on the inner diameter side. Therefore, the seal part 52 (which is originally shaped as indicated by the broken line) is caused to disform in the direction of the arrow. At the same time, the body seal lip 54 extending from the trim part 51 is also caused to fall, thus lessening the sealing effect of the weather strip 5B.